1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly to uplink multiple-input multiple-output (MIMO).
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division—Code Division Multiple Access (TD-CDMA), and Time Division—Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple user equipment devices (UE). Each UE communicates with one or more base stations, such as a Node B via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the Node Bs to the UEs, and the reverse link (or uplink) refers to the communication link from the UEs to the Node Bs. This communication link may be established via a single-in-single-out, multiple-in-single-out or a multiple-in-multiple-out (MIMO) system. Thus, for example, the system can utilize downlink and/or uplink MIMO to facilitate improved throughput, transmission reliability, communication range, and/or the like.